Holding assembly and transport arrangement for handling lenses and method for finishing lenses

ABSTRACT

A holding device ( 1 ) holds a lens ( 6 ) at its lens edge ( 5 ) with the aid of an adhesive connection ( 16, 17 ). The adhesive connection ( 16, 17 ) is applied only at one adhesive point or only at two spaced apart adhesive points ( 16, 17 ). A transport arrangement handles lenses ( 6 ) during hard coating in a dip trough. The transport arrangement includes a dip frame with receptacles for holding devices for lenses ( 6 ). Each holding device ( 1 ) provided with a lens ( 6 ) is positioned on the dip frame in such a manner that the lens ( 6 ) is positioned above its holding device ( 1 ). A method is provided for finishing lenses ( 6 ) wherein the lenses ( 6 ) are subjected to various sequential finishing steps of a finishing process and the lenses ( 6 ) are cemented to the same holding device during finishing. The application of adhesive is only at one adhesive point or at two spaced apart adhesive points ( 16, 17 ). A turning arrangement for turning a holding device ( 1 ) holding a lens ( 6 ) at its lens edge ( 5 ) includes a turning tooth system associated with the holding device ( 1 ) and a translatorily movable turning element that coacts with the turning tooth system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of internationalpatent application PCT/EP 2006/000573, filed Jan. 24, 2006, designatingthe United States and claiming priority from German application 10 2005004 006.3, filed Jan. 27, 2005, and the entire content of bothapplications is incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a holding assembly for manipulating lenses withat least one holding element especially during the surface treatment ofthe lenses. The invention also relates to a transport arrangement formanipulating lenses during the application of a hard coating in a diptrough with a dip frame for accommodating holding devices for thelenses. Finally, the invention relates to a method for finishing lenseswherein the lenses are subjected to different finishing steps insequence.

BACKGROUND OF THE INVENTION

EP 1295962 A1 discloses a spring holding assembly for lens edges. Such aspring holding assembly can lead to damage at the lens edges when heldtoo tightly and, when held too weakly, a holding force insufficient forthe manipulations is provided. Furthermore, it can be seen from thispublication that the lens can also be cemented into the holder.

SUMMARY OF THE INVENTION

A first object of the invention is to provide an assembly for holdingthe lenses, especially, spectacle lenses, which, during processing ofthe lenses, ensures a tight hold and, thereafter, the lens, especially aspectacle lens, can be removed without damaging the latter.

The holding assembly of the invention is for holding a lens at the edgethereof and includes: a holding device for holding the lens; the holdingdevice including an adhesive connection for holding the lens at the edgethereof; and, the adhesive connection being provided at only oneadhesive point or at only two adhesive points spaced from each other.

A tight connection is ensured because the holding element is cementableto the lens edge or is cementable with an adhesive element to the edgeof the lens. A breaking or scratching of the lens as is often the casein mechanical and especially in form-tight or force-tight connections issubstantially precluded. Furthermore, the embodiment of the inventionprovides for an arrangement wherein the holding device can be cementedat a point, namely, at one point or two points spaced from each other.One adhesive point can be sufficient but two adhesive points can improvethe stability. Point-shaped here does not mean that the adhesive pointdoes not have any spatial expansion. The expansion of the cementing inthe peripheral direction is, however, limited in that the supportsurface of the holding device, which is defined by the adhesive, doesnot follow the edge contour of the lens or only to a very limited extentand only so far that a sufficient connection is ensured between lens andholding device. A point fixation having a diameter of a few millimetersis sufficient for spectacle lenses usually used having a diameter ofapproximately 40 mm to 80 mm.

In an especially advantageous variation of the invention, the adhesiveconnection includes an adhesive element which can be cemented to theedge of the lens. An adhesive element of this kind can, for example, beconfigured in the nature of segments of a band and/or have a certainspatial expansion. Compared to a liquid adhesive, this variation affordsthe advantage that an adhesive element can be easily placed at theintended location.

The use of a liquid or pasty adhesive has the disadvantage that specialcaution must be used in order to prevent that the adhesive is applied toa non-wanted location, especially, to optically active surfaces of thelens. In this case, however, the strength of the adhesive connection isincreased even for smaller adhesive surfaces compared to an adhesivewhich, in general, requires an additional carrier. Furthermore, aprecise metering of the adhesive quantity is very easily possible. Thespatial expansion of the adhesive point can be individually adapted tothe available contact locations on the lens and on the holding element.Accordingly, it can be purposeful to select the point form (adhesivevolume) in dependence upon the thickness, especially edge thickness,and/or the size and/or the weight of the lens. The use of meteringsystems or multiaxial systems for orientating the position of the lensand holding device is likewise advantageous.

It has been shown to be advantageous to provide a holding element forapplying the one adhesive point or only two adhesive points whichholding element, preferably, projects from the actual holding deviceand/or is configured as a separate component. The application of theadhesive and the establishment of the adhesive connection itself issimplified thereby.

An especially advantageous variation of the invention provides for twoholding elements in the form of two holding arms arranged at an angle toeach other. These holding arms (preferably at the ends) are configuredfor applying respective adhesive points. A metering slot can be providedin each case which can accommodate a liquid or pasty adhesive, forexample, in the form of a caterpillar. The metering slot can, forexample, have a quadrilaterally-shaped outer contour, a roof-shapedouter contour or even the form of a spherically-shaped or cylindricaldepression. With a configuration of this kind, the adhesive is at thedesired location even if the actual location of application deviatesslightly from the ideal location because of adjustment inaccuracies orthe like.

The holding arms are preferably configured to be elastic in order tocompensate for stresses, for example, during tempering processes towhich the lens including the holding device is subjected.

Sensor means can be provided in order to detect the position, size andshape or the like of the lens as well as the instantaneous orientationto the holding device as may be required. This information can be usedto bring the lens into a pregiven position to the particular holdingelement of the holding device, for example, by means of a robot or thelike before the lens is cemented to the holding device. In this way, theinfluence of an operator and a source of error associated therewith isprecluded.

The lens, at its periphery, can have a certain amount of additionalmaterial, a so-called sacrificial geometry. This additional material canfunction as a defined adhesive interface or as a noncritical regionwhich can be cut away. Excessive lacquer, which is applied in a dipprocess, can be conducted away via the excess material with the lacquerleaving lacquer runoff traces during the subsequent drying operation.This excess material can be a geometry which is the same for a pluralityof lenses or the excess material can be a surface edging optimizedmathematically.

It is especially advantageous when the adhesive connection is producedwith a light-curing adhesive and especially an adhesive which is curedwith ultraviolet light. In this way, a controlled joining of the lensand holding device is possible. Lens and holding device can be broughtinto the desired position relative to each other without concern of acuring of the adhesive taking place. The use of a thermally-curingadhesive is also possible; however, especially some plastic lenses arenot temperature resistant to the desired extent so that the use of alight curing plastic is preferred. As an ultraviolet light source, onecan utilize long serving, highly efficient and space saving luminescentdiodes for cost saving reasons. In general, no radiation conductors arerequired. Furthermore, one does not need darkening shutters on the lightsource if the LEDs are switched on only during the exposure step. TheLEDs, as a rule, lose less heat because the output power is convertedexclusively in the required wavelength range.

In order to be able to cure the light-curing adhesive in a targetedmanner and from an easily accessible side of the holding device, it hasbeen shown to be very advantageous when the holding device (especially,the holding element or the holding elements) has a light transmittingregion for curing the adhesive. A light transmitting region of this kindcan, for example, be made available by utilizing a material, which isadequately light transmissive in the decisive spectral range, for themanufacture of the holding device. It is, however, also possible toconfigure the holding device locally transparent in the desired range,for example, by providing a cutout or introducing another material inthe holding device.

It has been further shown to be favorable when an inscription is appliedto the holding device by means of which this holding device can beclearly identified. The inscription can, for example, be applied withthe aid of a laser. The inscription can be a data matrix code or includethe same. The tracking of an individual order can take place via acorresponding standardized data matrix code (paperless manufacture).

It has been shown to be favorable when the holding device has a holdingelement for holding the holding device on a transport arrangement.Alternatively to a separable holding means, an attachment device can beprovided for preferably releasably attaching the holding device to atransport arrangement.

In the first mentioned case, it has been shown to be advantageous whenthe holding element is so configured or coacts in such a manner with thetransport arrangement that the holding device is held almost withoutcontact. An almost contactless holding is here understood to be thatmechanical forces operate only insofar as they are needed for thedefined orientation of the holding device with reference to thetransport arrangement but not with respect to the carrying support ofthe transport arrangement.

Preferably, the holding element has an element of a magnetic ormagnetizable material. Corresponding thereto, the transport arrangementhas a counterelement of a magnetizable or magnetic material in order tohold the holding element by means of a magnetic force almost withoutcontact. The holding element can, for example, be configured in themanner of a guide cylinder which has a round head with an integrated(magnetizable) steel core. The spherical head can, with the aid of amagnet assigned to the transport arrangement, be brought into a definedposition without the holding device being noticeably supported on thetransport arrangement.

It is understood that a holding element of the type noted above can beused also in conventional holders as they are known from the state ofthe art.

In a lens finishing process, namely, for example, when the lens isprocessed on the forward and rearward sides and is especially coated, ithappens again and again that one of the two sides is damaged when thelens is turned from one side to the other side. On the one hand, thiscan occur because a turning is often still done manually and, on theother hand, in general, an application to one of the two sides or to theedge takes place. The invention provides for a turning arrangement forturning the lens which is a component of the holding device. Turning thelens from one side to the other is then not necessary and the risk ofdamage to the lens is virtually precluded.

An especially simple variation of a turning arrangement for turning thelens comprises configuring the turning arrangement as a turning toothsystem.

In addition, it has been shown to be advantageous when an attachmentdevice is provided for attaching the holding device to a transportarrangement. It is advantageous when the attachment device is configuredas a latch unit. On the one hand, the connection is simple to make and,in general, can be again released. The manipulation is thereby greatlysimplified.

Finally, it is advantageous to provide means to ensure the holdingdevice against a rotation on the transport arrangement. A dropping outof the lens and a collision with items arranged in the vicinity isthereby substantially precluded.

In order to improve the adherence of the adhesive on the surface of theholding device intended therefor, the surface is at least partiallyconfigured in the manner of an orange skin on which the adhesive canvery well adhere and this is according to another feature of theinvention. At the same time, this surface provides that a lacqueradheres very well to the surface of the holding device so that it doesnot detach in subsequent process steps and precipitate onto the lenscarried by the holding device, for example, in a dip bath process.

Such a holding device can be used in the finishing of optical lenses inthe spectacle glass industry. The finishing process includes, generally,the stations: washing, hard coating, tempering and, if needed, theapplication of an antireflection coating as well as a so-called cleancoat coating. At the present time, different lens holders are used forthe individual stations at least in part because the lenses aremanipulated differently at each station.

The lenses are mostly circular in shape but can have forms which deviatetherefrom. The lens diameter runs generally between 40 to 80 mm.

With the arrangement of the invention for holding a lens, the lens canremain in a holder during the entire finishing process which is made upof several finishing steps.

In a preferred embodiment of a holding device for lenses held at thelens edge, this holding device is usable for a plurality of differentdiameters and geometric shapes of lenses. In the manufacture ofspectacle glass, diameters of 40 to 80 mm as well as elliptical lensesare usual. However, there are also spectacle lenses which have otherdimensions and geometric shapes. In addition, the arrangement of theinvention is not limited to spectacle lenses but can be utilizedeverywhere where lens-shaped objects are to be manipulated.

In one embodiment of the invention, the holding element can have a rodshape, especially a cylindrical rod shape having a flattening at the endto be cemented. However, other forms such as rectangles, triangles andpolygons, et cetera are possible. Also, the holding device can include aholding comb, at least one holding rider insertable into the holdingcomb and at least one adhesive element with which holding rider and lensedge can be connected. The holding riders can be provided with boreswherein a gripper can be introduced. The gripper can be part of thefully automatic finishing process of lenses.

Furthermore, it can be provided that the holding elements are configuredas a link chain having several link elements. These link elements canalso be provided with bores wherein a gripper can be introduced forfully automatically manipulating the finishing steps. An adhesiveelement can be assigned to at least one link chain element.

Holding elements of the most different configuration are conceivable.Preferably, injection molded disposable parts of polycarbonate are used.However, other materials can be used especially metals. Also, reusableholding elements can be used.

The adhesive elements can be configured as adhesive drops ordouble-sided adhesive bands. Of course, still other configurations ofadhesive elements are conceivable. Preferably, an adhesive is used whichcan be cured under ultraviolet light.

In a preferred embodiment of the invention, a holding element isprovided with a coding, especially, a prescription coding. The codingcan be configured as a data matrix code or bar code. Microchips or otherdata carriers are conceivable. The coding can contain the prescriptionvalues of a customer, for example, sphere, cylinder, axis as well asinvoice date and invoice number and additional data which is viewed asbeing helpful. Up to now, the prescription slip is always transportedparallel to the lens to be finished. Conventionally, this lens is takenin hand several times because different lens holders are used fordifferent finishing steps. Here, mix ups can result which must beavoided. With the direct application via the holding device to the lens,data can no longer become lost or be incorrectly assigned. The coding isstamped, impressed or applied with a laser.

It is a further object of the invention to provide a transportarrangement for manipulating lenses during the application of a hardcoating in a dip trough which makes it possible to coat lenses withoutthe formation of streaks or runoff traces caused by dripping fromholding devices.

The transport arrangement of the invention is for manipulating lensesduring the application of a hard coating in a dip trough. Thearrangement includes: a plurality of holding devices for holdingcorresponding ones of the lenses; a dipping unit having a frame definingreceiving members for receiving the holding devices thereon; and, theholding devices being arranged on the frame so as to cause each of thelenses to be disposed above and/or laterally of the holding deviceassigned thereto.

Residues from the dip bath can no longer slide onto the lenses from theholding device because the holding device, which is loaded with a lens,is so arranged on the dip unit that the lenses are disposed above and/orlaterally of their holding device.

The holding device can be arranged precisely perpendicularly under thelens. However, lateral arrangements are also conceivable as long as thecriterion is satisfied that no dip bath residues can reach the lenswhere the residue can cause streaks to form. For this purpose, a holdingdevice according to the invention can be used.

A further object of the invention is to provide a method for finishinglenses. The lenses are subjected to sequentially occurring differentfinishing steps without it being necessary to have an operator manuallytouch the lens.

The method of the invention is for finishing lenses wherein the lensesare subjected to different finishing steps of a finishing process insequence. The method includes the steps of: cementing each of the lenseswith adhesive to a corresponding one of a plurality of holding devicesat one point or at two points separated from each other; and,exclusively utilizing the same ones of the holding devices throughoutthe finishing process.

The lenses are exclusively connected to the same holding device duringthe finishing process. For this reason, the lenses need not be touchedby an operator as is conventional at the present time. Contaminationfrom shed skin, hairs, fingerprints are avoided and the danger of glassbreakage is less because no exchange of the holding device takes place.

In the method of the invention, the lens can be cemented to the holdingdevice.

The finishing process can include the finishing steps of: washing, hardcoating and tempering. The finishing process can include a finishingstep for applying an antireflection coating. The finishing process caninclude a finishing step for applying an anticontaminant coating.

A further object of the invention is to provide a turning unit forturning the lenses in the lens holders, for example, during thefinishing process. The turning arrangement is built up comparativelysimply and is robust and functions reliably and is comparatively costeffective to manufacture.

The turning arrangement of the invention for turning a holding deviceholding a lens at its lens edge is characterized in that it includes aturning tooth system assigned to the holding device and a translatorilymovable turning element coacting with the turning tooth system. Thetranslatorily movable turning element engages into the turning toothsystem of the holding device such that the translatory movement of theturning element is converted into a rotation movement rotating theholding device. The turning tooth system and the turning element arepreferably so matched to each other that the holding device completes a180° rotation so that the two sides of the lens can exchange theiralignment. If, for example, at first, the forward side of the lens iscoated, then the back side of the lens can be coated after turning.

It is sufficient when the turning tooth system includes only two teethbetween which the turning element can engage. A turning arrangement ofthe invention is therefore comparatively simply built up.

The turning tooth system is preferably arranged on the outer peripheryof a ring or circularly-shaped holding plate. The holding plate ispreferably rotatably arranged about a rotation center and is especiallysuspended or supported. This variation is characterized by its simplegeometric configuration and therefore is cost effective to manufacture.

The turning element can, for example, be configured as a pin which, forexample, can engage between the two teeth of the tooth system.

The turning element can, for example, be arranged on a wagon to which,for example, a translatory movement can be imparted via a chain or apull line. The turning element can also be part of the chain or pullline.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the drawingswherein:

FIG. 1 is a perspective view of a first embodiment of a holding deviceaccording to the invention having a rod configuration with coding;

FIG. 2 is an enlarged detail view of a portion of the holding device ofFIG. 1;

FIG. 3 is a perspective schematic of a second embodiment of the holdingdevice according to the invention with holding riders;

FIG. 4 is a perspective view of a third embodiment of a holding deviceaccording to the invention having interconnected links and coding;

FIG. 5 is a perspective view of a fourth embodiment of a holding deviceaccording to the invention having a holding spring. The holding springhas contact surfaces on which respective adhesive connections aregenerated. A holding spring is used for applying a hard coating. Theholding spring is complemented by a second cemented holding spring forthe finishing steps of an anti-reflection coating and a clean coating(hydrophobic coating);

FIG. 6 shows two segments of a lens holder having a sphericalconfiguration in accordance with the state of the art;

FIG. 7 is a cutaway view of a detail of a segment of aspherically-shaped lens holder according to the state of the art with alens and cemented holding springs as described with respect to FIG. 5;

FIG. 8 is a fifth embodiment of a holding device according to theinvention having two holding cylinders;

FIG. 9 is a perspective schematic of a transport arrangement accordingto the invention for manipulating lenses when they are supplied with ahard coating;

FIG. 10 is a holding device according to another embodiment of theinvention which carries a lens having a sacrificial geometry and this isshown compared to a holding device holding a lens without a sacrificialgeometry;

FIG. 11 is a sixth embodiment of a holding device according to theinvention having two elastic holding arms and a turning arrangement inplan view from above;

FIG. 12 shows the embodiment of FIG. 11 in a perspective view;

FIG. 13 is a side elevation view of the embodiment of FIG. 11;

FIG. 14 is a side elevation view of a wagon of the turning arrangementof FIG. 11;

FIG. 15 is a plan view of a seventh embodiment of a holding deviceaccording to the invention with two elastic holding arms as well as aturning arrangement of the invention;

FIG. 16 is a perspective view of the embodiment of FIG. 15;

FIG. 17 is a side elevation view of the embodiment of FIG. 15; and,

FIG. 18 is a side elevation view of a wagon of the turning arrangementof the invention of FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows a first embodiment of a holding device 1 having a firstholding element 2 and a second holding element 3. The first holdingelement 2 is cemented with an adhesive element 4 onto the lens edge 5 ofa lens 6. The second holding element 3 is cemented with an adhesiveelement 7 to the opposite-lying position of the lens 6 at its lens edge.The holding elements (2, 3) define support arms projecting from the lens6.

One such holding device 1 can be used in the finishing of lenses 6,especially, plastic lenses in the spectacles industry. A finishingprocess of this kind includes several finishing steps. Usually, thelenses 6 are subjected to a finishing process after the end of thegeometric shaping of the surface 10.

A first finishing step can be the washing of the lenses 6. Then acoating process can follow with wetting both surfaces wherein the lenses6 are provided with a hard coating. Thereafter, a tempering can takeplace during which the hard coating is strengthened. As furtherfinishing steps, various antireflection coatings can be applied. Inaddition, a hydrophobic coating for repelling dirt (clean coat) ispossible as a further finishing step. Most of these finishing steps takeplace in a high vacuum. In conventional methods, different holdingdevices are used for different finishing steps. With the device of theinvention, all finishing steps can be run through with one and the sameholding device (also in high vacuum).

The holding element (2, 3) is configured to be flattened or beveled inthe region of the end (8, 9) to be cemented. In this way, the holdingelement (2, 3) can also be attached well to thin lens edges without theadhesive mass reaching the lens surfaces 10 beyond the lens edge 5.

The lens 6 is preferably made of plastic, however, other materials, forexample, silicate lenses are conceivable. Also, polycarbonate lenses canbe used.

The holding device 1 can already be provided with adhesive elements (4,7). The adhesive element (4, 7) can be protected by a protective foilwhich is removed only shortly before the connection to the lens 6, forexample, the protective foil can be in the form of a double-sidedadhering adhesive foil. In lieu of such a foil type adhesive element (4,7), a drop of adhesive can be used which is only applied for cementingto the lens edge 5 at an end of the holding element (2, 3). The adhesivecan then cure in the air.

Preferably, an adhesive drop is applied with an adhesive nozzle. Curingis preferably provided under ultraviolet light. It can also be providedthat the (solid or liquid) adhesive element (4, 7) is applied to thelens edge 5 in order to cement the holding element (2, 3) to the lensedge 5. A point cementing is effected in accordance with the invention.

The holding elements (2, 3) are knocked off the lens edge 5 after thefinishing of the lens 6. It is also conceivable to dissolve the adhesiveconnection by means of a chemical agent or temperature differences ormechanically.

The holding element (2, 3) can be used again. Preferably, disposableparts are used which, for example, can be made by means of an injectionmolding process. The holding elements (2, 3) can be made ofpolycarbonate or other plastics. Other materials are also conceivable,for example, metals or ceramic.

The holding element 3 is provided with a flag 11 in the presentembodiment. A code is applied to the flag 11. This code 12 can includethe most varied data, for example, the code can include the prescriptionslip of the customer with spherical, cylindrical and axial values aswell as an order number, special wishes of the customer, order date,quality data and much more.

In conventional finishing steps, the prescription slip of the patient isof paper and runs next to the apparatus during the finishing process ofthe lens 6 corresponding thereto. Here, a mix-up can easily occur. Incontrast, in the holding device 1 according to the invention, theprescription slip is always connected to the corresponding lens 6 andcannot become lost or be assigned to an incorrect lens.

In FIG. 1, two holding elements 2 and 3 are shown and it is understoodthat only one holding element can be used. The adhesive element (4, 7)should provide an adequately high strength so that the lens 6 can besubjected to the most varied movement sequences during handling. Theconnection between the holding elements (2, 3), adhesive element (4, 7)and lens 6 should permit a transport of the lens in the horizontalwithout the lens tilting and falling off.

Lenses 6 of the most varied form and different diameter can bemanipulated with the holding device 1. Lenses are mostly configured tobe circular in shape but can have other forms, for example, oval formsor free forms. The lens diameters vary usually between 40 mm and 80 mm.Here too, deviations upwardly or downwardly are conceivable.

In FIG. 2, an enlarged cutaway portion of FIG. 1 is shown which clearlyemphasizes the adhesive point 4. With the adhesive point 4, the holdingelement 2 is cemented to the lens edge 5. With the adhesive point 4, theholding element 2 is cemented to the lens edge 5 and the adhesive pointdoes not extend over the lens edge 5 onto the lens surface 10. The lenssurface 10 can therefore be finished in its totality.

FIG. 3 shows a further holding device 1 comprising a holding comb 13,holding riders 14 and 15 and adhesive elements 16 and 17. The holdingcomb 13 is preferably a ring segment 18 having notches 19. Holdingriders (14, 15) are inserted into two of these notches 19. The holdingriders (14, 15) are inserted in different notches 19 depending upon thesize of the lens which is to be held. In this way, lenses 6 of differentdiameters can be held. The holding comb 13 can also have other forms inlieu of the form of a ring section 18, for example, the holding comb 13can have the form of an elliptical section. Bores (20, 21) are formed inthe holding riders 14 and 15. For the further handling, for example, agripper (not shown) can engage in the bores (20, 21) and, in this way,bring the lens 6 held from one finishing step to the next. A coding isnot shown but it is understood that a coding can be applied.

FIG. 4 shows a third embodiment of a holding device having a holdingelement in the form of a link chain 22 having four link elements (23,24, 25, 26). The link chain is connected to a lens 6 via adhesiveelements (27, 28, 29). Here, three possible positions for applying theadhesive elements are shown. It is, for example, conceivable to use onlythe adhesive elements 27 and 29. The adhesive element 28 can be eithercompletely omitted or can be provided with a protective foil so that noadhesion with the lens 6 takes place. The lenses 6 of the most differentgeometrical configuration can be held because of the different anglearrangements of the individual chain links 23 to 26. The number of chainlinks can vary, for example, in dependence upon the lens diameter andlens weight. Whereas only one or two of the chain links act to hold inthat they are cemented to the lens, the remaining chain links canfunction to support the lens.

A chain link 25 is provided with a code 12. This code can, for example,be impressed, stamped, laser signed or applied with adhesive.

The link chain 22 is also provided with bores (48, 49, 50) in thisembodiment wherein a gripper (not shown) can engage for the furthermanipulation.

FIG. 5 shows a fourth embodiment of a holding device 1 wherein theholding element 30 is configured similarly to a leaf spring. The holdingspring 30 is bent in the mid region 31 and is configured to have anS-shape in the two end regions (32, 33). The end piece (34, 35) of theS-shaped region is configured to be lengthened to the end of the holdingspring 30. Adhesive elements (36, 37) are applied to these end pieces(34, 35). The mid region 31 is provided with a slit 38. The holdingspring 30 is configured to be bendable. For this reason, the holdingspring 30 can be adapted to different radii of a lens edge (not shown).A gripper (not shown) can engage in the slots (39, 40) for the furthermanipulation in the finishing steps. The slots (39, 40) are defined bythe S-shape.

FIG. 6 shows two segments 41 of a spherically-shaped holder as used, forexample, in the coating with an antireflectant coating. Aspherically-shaped holder built up, for example, of 6 to 8 holdersegments 41 has, simplified, the form of a hollow spherical cap and isprovided with a plurality of holes 42 for lenses (not shown). The holes42 are provided with reference numerals only by way of example.

In FIG. 7, a lens 6 is seated in one such hole 42 of aspherically-shaped holder segment 41 shown as a cutaway portion. Thislens 6 has two holding springs 30 with two possibilities for cementing,respectively, as shown in FIG. 5. It is understood that the use of onlyone holding spring 30 is conceivable. The lens 6 is held well in thehole 42 by the holding spring 30 with some of the edge of the hole sidewall 43 engaging in the slit 38. For this purpose, the bending of themid region can be to a higher or lesser degree depending upon what isplaced into the hole 42 of the lens holder segment 41 for a good grip.With this arrangement in the hole, a good coating of the lens isguaranteed by the vapor coming from below.

FIG. 8 shows a further holding device 1 having two holding cylinders(44, 45) which are connected to the lens edge 5 of a lens 6 via adhesiveelements (46, 47). The holding cylinders (44, 45) have cross-shapedbores (54, 55) into which a gripper (not shown) having preferably across-shaped gripper arm can engage for further manipulation.

FIG. 9 shows a transport arrangement of the invention for manipulatinglenses 6 for applying a hard coating in a dip trough (not shown). Thetransport arrangement 51 has two grip rods (52, 53) of afully-automatically driven gripper (not shown) which, for example,accommodates three of the holding devices 1 shown in FIG. 3 and lowersthese holding devices into the dip trough (not shown) and thereafteragain takes the holding devices out of the dip bath and takes the sameto the next finishing step. The accommodation of the holding devices 1of FIG. 3 takes place in that the grippers (52, 53) are inserted intobores (20, 21) of the holding riders 14 and 15. With the arrangement ofthe holding device 1 below the lenses 6, a dripping is prevented afterthe dip operation from the holding device 1 onto the lens 6.

Spectacle lenses are often optimized with respect to their thickness.Plus glasses having optimized (that is, minimized) center thicknessestherefore often have an outer peripheral course wherein a holding via anadhesive in accordance with the invention can only be applied withdifficulty with the required holding stability. Preferably, the marginregions of the lens are at least provided with a suitable section.

FIG. 10 shows a holding device 1 which carries a spectacle lens 6 havingan optimized center thickness. To the left, the holding device 1 isshown when it carries a spectacle lens 6 finished in the conventionalmanner. The illustration on the right-hand side shows the holding device1 with a spectacle lens 6 having a sacrificial geometry 91. Thesacrificial geometry is an additional amount at the glass periphery 5 ofthe spectacle lens 6.

From the left-hand view, it can be seen that a lens 6 having a smallradius of curvature must be held at adhesive points 4 spaced veryclosely (distance d₁). The sacrificial geometry 91 can be so selectedthat its curvature permits to arrange the adhesive points 4 for holdingthe lens at a very large distance d₂. Furthermore, a sacrificialgeometry 91 of this kind affords the advantage that the adhesive points4 do not have to be arranged on the effective surface of the spectaclelens 6. Furthermore, it is possible to provide defined coordinates forthe location of the adhesive points 4. Finally, the outer contour of thesacrificial geometry 91 is adapted in such a manner to the holdingelements (2, 3) of the holding device 1 that there is always asufficient or optimal contact surface between sacrificial geometry 91and the holding elements (2, 3).

FIGS. 11 to 14 show a sixth embodiment of a holding device 1 accordingto the invention having two holding arms (59, 60) and a turningarrangement (81, 82, 83, 84, 68) in different views. FIG. 11 shows theholding device 1 together with the turning arrangement in plan view fromabove. FIGS. 12 and 13 show the holding device 1 in a perspective viewand a side elevation view, respectively. FIG. 14 shows the wagon 81 ofthe turning arrangement (81, 82, 83, 84, 68) of the invention in a sideelevation view.

The holding device 1 is based on a base plate 56, which is essentiallycircularly-shaped, as well as two holding arms (59, 60) which arearranged at an angle with respect to each other and at an angle withrespect to the base plate 56.

According to the invention, the holding device 1 is made of unbreakablematerial resistant to temperatures up to over 150° C. The material isfurther alkaline resistant, acid resistant, resistant to solvents aswell as being resistant to ultrasound in order to withstand cleaningprocedures, injection processes and rinsing processes. It can be used inhigh vacuum and in clean rooms. Furthermore, it dampens structure-bornevibrations. In the present embodiment, the holding device 1 isessentially one piece (see the description which follows) ofpolyphenylenesulphone.

The holding arms (59, 60) define a plane which is coincident essentiallywith the main plane of a lens to be accommodated (not shown here).Furthermore, the two holding arms (59, 60) have a certain elasticity inorder to take up tempering stresses or the like or to compensatetherefor without the accommodated lens sustaining damage.

The two elastic holding arms (59, 60) have, at their ends, respectiveheads (61, 62). Each of the heads (61, 62) is annularly-shaped in theform of an outer jacket (78, 79). Each of the outer jackets (78, 79)accommodates a light-transmitting cementing pin (63, 64) of materialpermeable to ultraviolet light. Polycarbonate is used in the presentembodiment. This light-transmitting cementing pin (63, 64) is configuredto have a cylindrical shape. Each light-transmitting cementing pin (63,64) has a flattened end as well as an end terminating in a roof-shapedtip. The tip-terminating end includes a metering slot (65, 66) foraccommodating an adhesive bead.

In order to connect a lens (not shown here) to the holding device 1, aliquid or pasty UV-hardening adhesive is placed in the metering slots(65, 66). The lens is seated on the two metering slots (65, 66) filledwith adhesive and this is done in such a manner that the imaginaryplane, which is formed by the holding arms (59, 60), and the main planeof the lens are essentially coincident. The holding arms (59, 60) arearranged at an angle to each other in such a manner and so dimensionedwith respect to their dimensions that lenses having radii between 20 and40 mm can be seated on the light-transmitting cementing pins (63, 64)without the outer edges of the lenses touching additional parts of theholding device 1. If now the adhesive, which is disposed in eachmetering slot (65, 66), is illuminated with the aid of a light conductor76 as indicated in FIG. 13 from behind with ultraviolet light throughthe respective cementing pins (63, 64), then the adhesive in themetering slot is cured and a point-shaped adhesive connection is formedwhich connects the outer edge of the lens to the holding device 1. Forclarity, the length of the adhesive is indicated with the aid of adouble arrow identified by reference numeral 77. Depending upon theapplication (here, for example, finishing lenses), it is important thatthe adhesive satisfies the requirements, which are imposed on theholding device 1, such as temperature resistance, acid resistance and/oralkaline resistance, et cetera.

The entire surface of the holding device 1 is configured in the mannerof an orange skin. In this way, a reliable adherence of lacquer to theholding device is ensured during the application of a hard coating tothe lens thereby preventing a separation of the lacquer from the holdingdevice in further processing steps such as washing.

The two holding arms (59, 60) have respective grip surfaces (74, 75)which are here so configured that a mechanical gripper can grip theholding device 1. It can also be configured somewhat larger than shownin FIG. 11 in order to make gripping by a person possible.

The connection between the base plate 56 and the holding arms (59, 60)takes place via two vertical webs (57, 58) which project essentiallyperpendicularly from the surface 69 of the base plate. These verticalwebs (57, 58) are here configured to have the shape of annular segmentsfor reasons which will be explained hereinafter.

The base plate 56 has a central opening so that a cylindrical pin (notshown here) can be introduced through this opening and the inner wallsof the vertical webs (57, 58) from the rear side (indicated here byreference numeral 71) of the base plate 56. The opening in the baseplate 56 additionally includes a slot which functions as a bayonet guide72 for the cylindrical pin with an appendage, which is introduced frombelow, whereby a relative movement between the holding device 1 and thepin (which, for example, is a component of the transport arrangement) isprevented.

At the inner periphery of the vertical webs (57, 58), there is an indexbore 70 which functions to axially fix the holding device 1 on thecylinder pin of the transport arrangement (not shown) and to accommodatethe holding device 1 in a spherically-shaped member. The surface 69 isconfigured as a support device or end position latch surface 73 for alatch nose assigned to the cylindrical pin of the transport arrangement(not shown) whereby the holding device 1 can be held so that it does notdrop off but is releasable from the transport arrangement. The lowerside of the base plate 56 functions as a contact/support surface 71 ofthe holding device 1 on the transport arrangement.

The base plate 56, which is essentially annular in shape, has a turningtooth system (67, 68) at the peripheral outer side and at both sides tothe plane defined by the two holding arms (59, 60). Basically, it wouldbe sufficient to provide such a turning tooth system 67 or 68 only onone side of the imaginary plane. Each of these turning tooth systems(67, 68) comprises essentially three teeth in the present embodimentbetween which a guide pin (82, 83, 84) or a tooth of another toothsystem or the like can grip.

The holding device 1 can, for example, be rotatably journalled with theaid of a cylindrical pin (as described above but not shown) which isguided through the opening in the base plate 56. Then, a translatorymovement of a pin 82 effects a rotational movement of the holding device1 about the axis defined by the cylindrical pin guided in the opening inthe base plate 56. The pin 82 engages between the three teeth of theturning tooth system (67, 68).

The turning pin 82, which engages in the turning tooth system 68, can bea component of a wagon 81 as shown, for example, in FIGS. 11 and 14. Ifthe wagon 81 is moved from the right to the left as shown in thedrawing, then the holding device 1 executes a turning movement of 180°about the rotational axis explained above. The sides of the lens therebytranspose their position. It is also possible to arrange or configurethe turning tooth system 68 and the turning pin 82 in such a manner thata rotational movement of more than 180° or less than 180° takes place.

The surface of the base plate 56 and/or a side surface of a holding arm(59, 60) functions as an inscription surface for applying a matrix codefor the work flow or process parameter control. All surfaces areinclined by at least 2° with respect to the lower contact/supportsurface 71 in order to always ensure a runoff of liquid after carryingout a dip process or washing process. In connection herewith, sharpedges are provided which prevent fluid from collecting.

FIGS. 15 to 18 show a seventh embodiment of a holding device 1 accordingto the invention having two arms (59, 60) and a turning arrangement (81,82, 83, 84, 68) in different views. FIG. 15 shows the holding device 1together with a turning arrangement in top plan view. FIG. 16 shows theholding device 1 in a perspective view and FIG. 17 in a side elevationview. FIG. 18 shows the wagon 81 of the turning arrangement (81, 82, 83,84, 68) in a side elevation view.

The holding device 1 of FIGS. 15 to 17 is configured very similarly tothe holding device 1 shown in FIGS. 11 to 13. Here too, the holdingdevice 1 includes a base plate 56 having an outer peripheral turningtooth system (67, 68) as well as two holding arms (59, 60) having endheads (61, 62).

In this embodiment, the heads (61, 62) are not, however, configured inthe form of outer jackets (78, 79); instead, the heads (61, 62) are madeof a unitary bulk material. Polycarbonate was used here as a bulkmaterial. This material has the required resistance with respect to thedifferent atmospheres in lens finishing. Furthermore, this materialensures a transmitted light illumination for curing the adhesiveconnecting lens and holding device 1. For the sake of completeness, theregion which is at least permeable for ultraviolet light is identifiedby reference numeral 85.

The base plate 56 has here no opening for accommodating a pin of atransport arrangement; instead, the base plate 56 itself carries acarrier cylinder 87 directed downwardly. The carrier cylinder 87carries, at its end, a spherical head 88 whereby the carrier cylinder 87can be inserted into an opening in a transport arrangement or the like.The carrying cylinder 87 includes a peripherally-extending guide slot 90whereinto a latch projection or the like of the transport arrangementcan be introduced and guided into engagement in order to align thecarrier cylinder 87 in the axial direction with respect to the transportarrangement. The guide slot 90 includes a fixation bore 89 in order tofix the carrier cylinder 87 in the peripheral direction in a definedposition (and therewith the entire holding device 1) by means of acorresponding counterelement assigned to the transport arrangement.

The insertable sphere 88 further has the purpose that the holder 1 canbe placed on only two support tips. The insertable sphere 88 has a steelcore. In this way, the holding device 1 can be held via a strong magnetin the vertical almost without contact (except for the tips). In a dipprocess, it is hereby avoided that the holder 1, because of a lacquerdeposited during the dip process, becomes stuck in the transport frameof the transport arrangement.

It is understood that the foregoing description is that of the preferredembodiments of the invention and that various changes and modificationsmay be made thereto without departing from the spirit and scope of theinvention as defined in the appended claims.

LIST OF REFERENCE NUMERALS

List of Reference Numerals 1. Holding device 2. First holding element 3.Second holding element 4. Adhesive element 5. Lens edge 6. Lens 7.Adhesive element 8. Flattened end region 9. Flattened end region 10.Lens surface 11. Flag 12. Code 13. Holding comb 14. Holding rider 15.Holding rider 16. Adhesive element 17. Adhesive element 18. Annularsector 19. Notch 20. Bore 21. Bore 22. Link chain 23. Link element 24.Link element 25. Link element 26. Link element 27. Adhesive element 28.Adhesive element 29. Adhesive element 30. Holding spring 31. Mid region32. S-shaped region 33. S-shaped region 34. End piece 35. End piece 36.Adhesive element 37. Adhesive element 38. Slit 39. Slot 40. Slot 41.Spherically-shaped segment 42. Holes 43. Hole side wall 44. Holdingcylinder 45. Holding cylinder 46. Adhesive element 47. Adhesive element48. Bore 49. Bore 50. Bore 51. Transport arrangement 52. Grip rod 53.Grip rod 54. Bore 55. Bore 56. Base plate 57. Vertical web 58. Verticalweb 59. Elastic holding arm 60. Elastic holding arm 61. Head 62. Head63. Transmitted light cementing pin of polycarbonate 64. Transmittedlight cementing pin of polycarbonate 65. Metering slot for adhesive 66.Metering slot for adhesive 67. Turning tooth system 68. Turning toothsystem 69. Surface 70. Index bore 71. Contact/support surface 72.Bayonet guide 73. End position latch surface 74. Grip surface 75. Gripsurface 76. Light conductor 77. Adhesive length 78. Outer jacket 79.Outer jacket 80. Inscription surface for identification signature 81.Wagon 82. Guide pin 83. Guide pin 84. Guide pin 85. Region oftransparent material 86. Shading for transmitted light 87. Carryingcylinder 88. Insertion sphere having integrated steel core 89. Fixationbore 90. Guide slot 91. Sacrificial geometry

1. A method for finishing lenses wherein the lenses are subjected todifferent finishing steps of a finishing process in sequence with saidlenses each having a peripheral edge, the method comprising the stepsof: cementing each of the lenses with adhesive to a corresponding one ofa plurality of holding devices at one point on said peripheral edge orat two points on said peripheral edge separated from each other; and,exclusively utilizing the same ones of said holding devices throughoutsaid finishing process.
 2. A method for finishing lenses wherein thelenses are subjected to different finishing steps of a finishing processin sequence, the method comprising the steps of: cementing each of thelenses with adhesive to a corresponding one of a plurality of holdingdevices at one point or at two points separated from each other;exclusively utilizing the same ones of said holding devices throughoutsaid finishing process; each of said holding devices comprising aholding comb defining at least one receptacle; a holding rider pluggableinto said receptacle; and, an adhesive element for cementing saidholding rider to the edge of the lens.
 3. The method of claim 2, whereinsaid finishing process includes the steps of washing, hard coating andtempering said lenses.
 4. The method of claim 2, wherein said finishingprocess includes the finishing step of applying an antireflectioncoating to said lenses.
 5. The method of claim 2, wherein said finishingprocess includes the finishing step of applying a dirt repellent coatingto said lenses.
 6. A turning arrangement for turning a lens having anedge, the turning arrangement comprising: a holding device holding saidlens at said edge thereof; a turning tooth system operatively connectedto said holding device; and, a translatorily movable turning elementcoacting with said turning tooth system to impart a turning movement tosaid holding device.
 7. The turning arrangement of claim 6, wherein saidturning tooth system has at least two teeth.
 8. The turning arrangementof claim 6, wherein said turning tooth system includes an annular orring-shaped holding plate having an outer periphery; and, teeth formedin said plate at said outer periphery.
 9. The turning arrangement ofclaim 6, wherein said turning element comprises a pin.
 10. The turningarrangement of claim 9, further comprising a movable wagon or carriageand said pin being mounted on said movable wagon or carriage.
 11. Themethod of claim 1, wherein each of said holding devices comprises aholding comb defining at least one receptacle; a holding rider pluggableinto said receptacle; and, an adhesive element for cementing saidholding rider to the edge of the lens.
 12. The method of claim 1,wherein said finishing process includes the steps of washing, hardcoating and tempering said lenses.
 13. The method of claim 1, whereinsaid finishing process includes the finishing step of applying anantireflection coating to said lenses.
 14. The method of claim 1,wherein said finishing process includes the finishing step of applying adirt repellent coating to said lenses.
 15. The method of claim 1,wherein each of said lenses is held only at the peripheral edge thereofand not otherwise.